Jun 5

As you know, back in May we celebrated our 11th birthday, and to mark the occasion we asked our followers to vote for their favourite Arkive highlight from the past year. A huge thank you to everyone who filled out the survey, it has been fantastic to get your feedback on what we have been doing and to find out what you felt was the most important focus for Arkive.

The results are now in and we are thrilled to announce that you chose our work profiling the world’s most endangered species as your winner. This has been a key aim for Arkive since the very beginning, and today we have over 16,000 species profiles in our collection. Of course, this work wouldn’t be possible without the support of the world’s best wildlife filmmakers and photographers, conservationists and scientists, who contribute their imagery and lend their support and advice.

Why not dive in and discover something new today?

Cotton-headed tamarin

The stunning cotton-headed tamarin is one of South America’s most endangered primates

Our 11th birthday also seemed like the ideal opportunity to give the Arkive website a fresh new look and feel, making the most of our amazing imagery. Check out our beautiful new homepage today.

May 24

Russian sturgeon (Acipenser gueldenstaedtii)

Species: Russian sturgeon (Acipenser gueldenstaedtii)

Status: Critically Endangered (CR)

Interesting Fact: The Russian sturgeon can reach lengths of nearly two and a half metres.

More information: The Russian sturgeon belongs to an ancient and unique group of fish, relics from the time of the dinosaurs. This prehistoric giant was formerly found in the Black, Azov, and Caspian Seas in Eastern Europe and the Middle East, as well as the deep sections of fast-flowing rivers, such as the Volga, Danube, and Ural Rivers. Populations of this species are now mostly found in the lower reaches of these river systems and along coastlines.

The male Russian sturgeon does not reproduce until it is between 8 and 13 years old and only do so every 2 or 3 years, while the female does not reach sexual maturity until it is 10 to 16 years old and then only reproduces every 4 to 6 years. There are two distinct forms of this fish species, the anadromous type which migrates up rivers from the sea to spawn and the freshwater form which remains in its freshwater habitat to spawn, although this form is now thought to be extinct. For the anadromous type, there are two separate migrations, one in spring when spawning occurs in the lower levels of the river and one in autumn when individuals migrate into freshwater where they spend the winter before spawning upstream the following spring.

Vast areas of the Russian sturgeon’s spawning grounds have been lost due to damming and exploitation. Dam construction is highly detrimental to this and other migratory fish species, as the usual migration routes to its spawning grounds are blocked, meaning that individuals either do not reproduce, or spawn in unsafe areas. Pollution in the Caspian and Black Sea basins is causing hormonal imbalances in this species and subsequently a greater number of hermaphroditic, infertile individuals are found in these areas.

The Russian sturgeon was once very important commercially, and its caviar was one of the most sought after of any species. Illegal fishing still continues, despite legal catch quotas being in place, with the illegal catch thought to far surpass the legally set limits. The Russian sturgeon is unprotected in many areas throughout its range and the absence of a strict monitoring system makes the control of fishing very difficult. Despite restocking efforts, the creation of artificial spawning grounds, and the introduction of fish lifts to help individuals to get around dams, the population is still in decline and over the last 15 years, global catches have dropped by 98 percent. As a slowly maturing species, it does not have the ability to recover from overexploitation, especially without complete cessation of fishing.

Celebrate World Fish Migration Day and find out more about why we need to protect these species and their habitats.

Find out more about sturgeon conservation.

See images of the Russian sturgeon on ARKive.

Hannah Mulvany, ARKive Content and Outreach Officer

Mar 8

Boreal felt lichen (Erioderma pedicellatum)

Species: Boreal felt lichen (Erioderma pedicellatum)

Status: Critically Endangered (CR)

Interesting Fact: The boreal felt lichen is known as the ‘panda bear’ of lichens because of its extreme rarity.

The boreal felt lichen is a ‘leafy’ species that grows on the branches and trunks of trees. When hydrated, it has a bluish-grey colour, but when dry it is darker grey-brown. The edges of this lichen typically curl up to expose whitish undersides.

The boreal lichen consists of two different organisms, a ‘mycobiont’ (a fungus) and a ‘phycobiont’ (a cyanobacterium – a bacterium that can photosynthesise), which live together in a symbiotic association.  The presence of the cyanobacteria makes the boreal felt lichen particularly sensitive to atmospheric pollution such as acid rain.

The boreal felt lichen was formerly known from Norway, Sweden, and Canada. Today, the species is thought to be restricted to two disjunct populations: a boreal population on Newfoundland, and a vastly depleted Atlantic population on Nova Scotia. The remaining populations are found in cool, moist, old-growth coniferous forests, and grow predominately on the trunks of balsam fir (Abies balsamea).

In addition to being highly sensitive to atmospheric pollutants such as acid rain, the boreal felt lichen is extremely vulnerable to habitat loss. Logging and air pollution have contributed towards a decline of more than 90% of the Atlantic population.

The Atlantic population of the boreal felt lichen is protected in Canada under the Federal Species at Risk Act (SARA), and is the focus of an ongoing recovery strategy. Crucially, efforts are being made, through land purchases and agreements with landowners, to formally protect areas of forest that are home to this rare species. Furthermore, conservationists are engaging with private and government forest managers to encourage their participation in the mapping of boreal felt lichen habitats and the implementation of management plans that will prevent further habitat loss.

Find out more about the boreal felt lichen at the Government of Canada Species at Risk Public Registry.

See images of the boreal felt lichen on ARKive.

Phoebe Shaw Stewart, ARKive Text Author.

Mar 1
Female addax and young

Addax (Addax nasomaculatus)

Species: Addax (Addax nasomaculatus)

Status: Critically Endangered (CR)

Interesting Fact: An addax is able to obtain all the water it requires from the food it consumes.

The addax is a desert antelope that is well adapted to its harsh habitat. It has splayed hooves that help it to travel more easily across sand. Its short, glossy coat is grey-brown in winter, fading to almost white during the summer, and both sexes possess the distinctive long, twisted horns.

These antelope are mainly active during the night. In the day, they dig ‘beds’ into the sand in shady areas to avoid the heat of the desert sun, which also shelters them from sandstorms. Small nomadic herds of this species spend the majority of their time wandering in search of food. These herds previously contained around 20 individuals, but today they are found in groups of four or less.

Once found across northern Africa, wild addax populations now only exist in a fragment of their former range. This dramatic decrease is mainly attributed to over-hunting, as their meat and leather is prized by local people. Other factors contributing to their decline include desertification, drought and habitat encroachment. It is estimated that fewer than five hundred individuals survive in the wild today, with the bulk of these found between the Termit region in eastern Niger and the Bodélé region in western Chad.

International trade of the addax is prohibited and the Sahara Conservation Fund has developed a regional strategy to protect the remaining wild populations and facilitate the re-colonisation of suitable habitats. A protected population exists in the Yotvata Hai-Bar Nature Reserve in Israel that was set up in 1968 to bolster populations of endangered desert species. There are currently around 2,000 individuals in captivity around the world that are being used in reintroduction programmes in Tunisia and Morocco.

Find out more about the addax at the Sahara Conservation Fund and WildAddax.

See images and videos of the addax on ARKive.

Phoebe Shaw Stewart, ARKive Text Author

Feb 22
Bermuda cave amphipod (<em>Pseudoniphargus grandimanus</em>)

Bermuda cave amphipod (Pseudoniphargus grandimanus)

Species: Bermuda cave amphipod (Pseudoniphargus grandimanus)

Status: Critically Endangered (CR)

Interesting Fact: Juvenile Bermuda cave amphipods are found far closer to the shore than adults.

More information:

The Bermuda cave amphipod is a colourless, eyeless amphipod that lacks a rostrum (a forward-projecting spine found between the eyes of most crustaceans). The upper lip is broadly rounded and the lower lip has large inner lobes. Male Bermuda cave amphipods are known to reach lengths of 6.5 to 8 millimetres.

The Bermuda cave amphipod is found in anchialine caves. These are coastal caves that are flooded with seawater via subterranean connections with the ocean. This species has been found in water of varying levels of salt concentration throughout a wide variety of anchialine limestone cave and groundwater habitats. Juvenile Bermuda cave amphipods are found far closer to the sea coast than adults, typically just 11 to 180 metres away, compared to 147 to 853 metres for adults.

Large adults, but notably no specimens carrying eggs, have been found further inland from the sea coast than juveniles. This could indicate a dependence on coastal marine habitats for reproduction, and that juveniles may migrate inland to mature.

The Bermuda cave amphipod is endemic to Bermuda, as its name suggests. Is has been recorded from wells, waterworks and cave waters in Hamilton, St George’s, Devonshire, Paget, Smith’s and Warwick Parishes in Bermuda. Caves in which it has been found include Church, Wonderland, Admiral’s and Government Quarry Caves.

 

Find out more about the Bermuda cave amphipod at Anchialine Caves and Cave Fauna of the World.

See images of the Bermuda cave amphipod on ARKive.

Phoebe Shaw Stewart, ARKive Text Author

 

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